I tend to use E-books due to my commute - I read on subways and trains, and they work better for that. Less weighty and cumbersome. My physical therapist told me to lighten my load ages ago. So a light e-book vs. a weighty paperback/hardback.

Also when commuting, it's nice to have privacy. I don't always want people to see the book that I'm reading.

I'm waiting to get Tomorrow and Tomorrow and Tomorrow - until I finish reading the ten books that I recently bought. (Or so I'm telling myself. I have a tendency to compulsively buy books to make myself feel better. Some people shop for shoes or clothes, or jewelry, I shop for books.)